Influenza Update 2019

South Africa carries a heavy influenza burden with more than 12000 deaths each year due to influenza associated severe acute respiratory illness. The most effective strategy to prevent influenza is vaccination.

Vaccination

Administer the vaccine each year because the virus continuously evolves. Vaccinate preferably before the influenza season (which can start any time from the last week in April to the first week in July). An adequate immune response takes about 2 weeks to develop.

• The trivalent vaccines for use in the 2019 southern hemisphere influenza season contain the following:
  • an A/Michigan/45/2015 (H1N1)pdm09-like virus; and
  • an A/Switzerland/8060/2017 (H3N2)-like virus; and
  • a B/Colorado/06/2017-like virus (B/Victoria/2/87 lineage)

Deaths in females of childbearing age in South Africa occur mostly in HIV-infected individuals with the mortality 3-fold higher in pregnant compared to non-pregnant women.

Influenza vaccine should be administered to:

1. Pregnant women irrespective of stage of pregnancy and up to 2 weeks after delivery
2. Persons at high risk for influenza and its complications (adults and children):
   1. Pulmonary diseases (e.g. asthma, COPD, Tb)
   2. Cardiac diseases (e.g. congestive cardiac failure), except hypertension
   3. Metabolic disorders (e.g. diabetes)
   4. Renal disease
   5. Hepatic disease
   6. Certain neurologic and neurodevelopmental conditions, including disorders of the brain, spinal cord, peripheral nerve and muscle such as cerebral palsy; epilepsy (seizure disorders); stroke; mental retardation; moderate to severe developmental delay; muscular dystrophy; spinal cord injury
   7. Haemoglobinopathies (e.g. sickle cell disease)
   8. Immunosuppression (e.g. HIV, immunosuppressive medication, malignancy)
3. Healthcare workers
4. Residents of old-age homes and chronic care and rehabilitation institutions
5. Persons > 65 years of age
6. Persons aged 6 months to 18 years on long-term aspirin therapy
7. Children 6 months to 59 months of age
8. Adults and children who are family contacts of high risk patients
9. Any person wishing to minimise the risk of influenza, especially in industrial settings, where large-scale absenteeism could cause significant economic losses